I love them too. When I was pregnant with DD2 I desperately researched them as I wasn't allowed to carry anything.
I also looked up reviews of the ones you have mentioned as well as the one from one of the TV shopping ads.
All except the Bissell rated quite poorly in terms of function or manufacturing quality.
I couldn't find anywhere except online to buy the Bissell (not unusual for here) but they wanted to charge so much for postage that we bought a roomba instead.